Patent GB-364574-A (GB)
Title: Improvements in the manufacture and production of fatty acids
IPC: C07C51/487
Filed: 1930-10-06
Abstract: Fatty acids which have been produced by the oxidation of hydrocarbons with nitric acid or nitrogen oxides, are freed from their nitrogen content by heating with alkalies or alkaline earths or with inorganic acids at temperatures of preferably 150-300 DEG  C. for the alkaline treatment, caustic soda, caustic potash, or an alkaline earth such as lime may be used, preferably in excess of the quantity necessary to saponify the acids.  The nitrogen compounds are mostly volatile and the non-volatile portion is dissolved by the inorganic acid used for liberating the fatty acids after the treatment.  If it is intended to use the acids for soap-making, the purified product instead of being precipitated with inorganic acid, is treated with enough vegetable, animal or purified synthetic fatty acid to combine with the excess of alkali.  In the purification by means of acids, the crude oxidation product is heated with dilute mineral acids such as 5-50 per cent sulphuric, phosphoric, or hydrochloric acid at similar temperatures and pressures, the nitrogen compounds dissolving in the acid and being separated in the aqueous layer after treatment. When the crude oxidation product has been bleached with chlorine in presence of water or with hypochlorous acid, the hydrochloric acid produced may be used for the acid purifying treatment.  In examples (1) the oxidation product, containing 2,5 per cent nitrogen, is mixed with excess of a 20 per cent aqueous caustic soda and heated in an autoclave for 3 hours to 150-181 DEG  C. nitrogen or like inert gas being blown through to expel the volatile nitrogen products; the unoxidized hydrocarbon is then separated, and the soap is treated with hydrochloric acid to precipitate the free fatty acids; (2) the oxidation product containing 3,5 per cent nitrogen is heated with an equal volume of 6N sulphuric or phosphoric acid or 2N hydrochloric acid for 2 hours at 170 DEG  C., the product being washed with water. Specifications 299,149, 324,492, 324,538, and 330,921, [all in Class 2 (iii), Dyes &c.], are referred to.ALSO:Fatty acids which have been produced by the oxidation of hydrocarbons with nitric acid or nitrogen oxides, are freed from their nitrogen content by heating with alkalies or alkaline earths or with inorganic acids at temperatures of preferably 150-300 DEG  C. In the alkaline treatment, caustic soda caustic potash, or an alkaline earth such as lime may be used, preferably in excess of the quantity necessary to saponify the acids.  The nitrogen compounds are mostly volatile and the non-volatile portion is dissolved by the inorganic acid used for liberating the fatty acids after the treatment.  If it is intended to use the acids for soap-making, the purified product, instead of being precipitated with inorganic acid, is treated with enough vegetable, animal, or purified synthetic fatty acid to combine with the excess of alkali.  In the purification by means of acids, the crude p oxidation product is heated with dilute mineral acids such as 5-50 per cent sulphuric, phosphoric, or hydrochloric acid at similar temperatures and pressures, the nitrogen compounds dissolving in the acid and being separated in the aqueous layer after the treatment, When the crude oxidation product has been bleached with chlorine in presence of water or with hypochlorous acid, the hydrochloric acid produced may be used for the acid purifying treatment.  In examples, (1) the oxidation product, containing 2,5 per cent nitrogen, is mixed with excess of a 20 per cent aqueous caustic soda and heated in an autoclave for 3 hours to 150-180 DEG  C., nitrogen or like inert gas being blown through to expel the volatile nitrogen products; the unoxidized hydrocarbon is then separated, and the soap is treated with hydrochloric acid to precipitate the free fatty acids; (2) the oxidation product containing 3,5 per cent nitrogen is heated with an equal volume of 6 N sulphuric or phosphoric acid or 2N hydrochloric acid for 2 hours at 170 DEG  C., the product being washed with water. Specifications 299,149, 324,492, 324,538, and 330,921, [all in Class 2 (iii), Dyes &c.], are referred to.